Mobile terminal apparatus, base station apparatus and communication control method

ABSTRACT

To optimize operation of a mobile terminal apparatus when a Half-duplex FDD scheme is applied, the mobile terminal apparatus performs radio communications with a base station apparatus by HD-FDD, and when transmission timing of an uplink signal and reception timing of a downlink signal overlaps each other, selectively performs transmission processing of the uplink signal and reception processing of the downlink signal, based on a priority relationship defined between the uplink signal and the downlink signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of and, thereby,claims benefit under 35 U.S.C. §120 to U.S. patent application Ser. No.13/980,319, filed on Jul. 18, 2013, titled, “MOBILE TERMINAL APPARATUS,BASE STATION APPARATUS AND COMMUNICATION CONTROL METHOD,” which is anational stage application of PCT Application No. PCT/JP2012/053818,filed on Feb. 17, 2012, which claims priority to Japanese PatentApplication No. 2011-033388 filed on Feb. 18, 2011. The contents of thepriority applications are incorporated by reference in their entirety.

TECHNICAL FIELD

Embodiments of the invention relate to a mobile terminal apparatus, basestation apparatus and communication control method in thenext-generation mobile communication system.

BACKGROUND ART

In UMTS (Universal Mobile Telecommunications System) networks, for thepurpose of improving spectral efficiency and further improving datarates, by adopting HSDPA (High Speed Downlink Packet Access) and HSUPA(High Speed Uplink Packet Access), it is performed exploiting maximumfeatures of the system based on W-CDMA (Wideband Code Division MultipleAccess). For the UMTS network, for the purpose of further increasinghigh-speed data rates, providing low delay and the like, Long TermEvolution (LTE) has been studied (Non-patent Literature 1).

In the 3G system, a fixed band of 5 MHz is substantially used, and it ispossible to achieve transmission rates of approximately maximum 2 Mbpsin downlink. Meanwhile, in the LTE system, using variable bands rangingfrom 1.4 MHz to 20 MHz, it is possible to achieve transmission rates ofmaximum 300 Mbps in downlink and about 75 Mbps in uplink. Further, inthe UMTS network, for the purpose of further increasing the wide-bandand high speed, successor systems to LTE have been studied (for example,also called LTE Advanced (LTE-A) or LTE Enhancement).

In such a system, as a duplex scheme applied to radio systems, there area Frequency Division Duplex (FDD) scheme and Time Division Duplex (TDD)scheme. In the FDD scheme, different frequency bands spaced a sufficientinterval are used in uplink and downlink. In the TDD scheme, the samefrequency band is used in uplink and downlink, and uplink communicationsand downlink communications are divided by time. In the FDD scheme, itis necessary to adequately widen the interval between the frequencybands used in uplink and downlink, and therefore, not only the basestation apparatus but also the mobile terminal apparatus require aduplexer with high accuracy.

Further, mobile terminal apparatuses (Rel. 8 or later) of LTE system andits successor system support also a Half-duplex FDD scheme. In theHalf-duplex FDD scheme, as in the FDD scheme, different frequency bandsare used in uplink and downlink, while uplink communications anddownlink communications are switched by time. Therefore, mobile terminalapparatuses do not need a duplexer with high accuracy, and it ispossible to simplify the mobile terminal apparatuses.

CITATION LIST Non-Patent Literature

-   [Non-patent Literature 1] 3GPP, TR25.912 (V7.1.0), “Feasibility    study for Evolved UTRA and UTRAN”, September 2006

SUMMARY OF THE INVENTION Technical Problem

However, in mobile terminal apparatuses in the case where theHalf-duplex FDD scheme is applied, optimization of operation stillremains as an issue.

The present invention was made in view of such a respect, and it is anobject of the invention to provide a mobile terminal apparatus, basestation apparatus and communication control method that enable theHalf-duplex FDD scheme to be optimized.

Solution to Problem

A mobile terminal apparatus of the invention is a mobile terminalapparatus that performs radio communications with a base stationapparatus by a half-duplex scheme, and is characterized by having atransmission/reception section configured to transmit an uplink signalto the base station apparatus, and receive a downlink signal from thebase station apparatus, and a control section configured to cause thetransmission/reception section to selectively perform transmission ofthe uplink signal and reception of the downlink signal, based on apriority relationship defined between the uplink signal and the downlinksignal, when transmission timing of the uplink signal and receptiontiming of the downlink signal overlaps each other.

Technical Advantage of the Invention

According to the invention, in the mobile terminal apparatus, whentransmission timing of the uplink signal and reception timing of thedownlink signal overlaps each other, transmission and receptionprocessing is selectively performed. Accordingly, it is possible tocause the mobile terminal apparatus to which the half-duplex scheme isapplied to perform optimal operation when transmission timing of theuplink signal and reception timing of the downlink signal overlaps eachother.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view of a system band of an LTE system;

FIG. 2 is an explanatory view of a Half-duplex FDD scheme;

FIGS. 3A, 3B, 3C, and 3D contain operation explanatory views of a mobileterminal apparatus when uplink transmission timing and downlinkreception timing overlaps each other;

FIG. 4 is a table showing an example of a priority relationship betweenuplink signals and downlink signals;

FIGS. 5A, 5B, and 5C contain explanatory views of transmission/receptionmethods of uplink signal and downlink signal in the same subframe;

FIG. 6 is an explanatory view of a system configuration of a radiocommunication system;

FIG. 7 is an entire configuration diagram of a base station apparatus;

FIG. 8 is an entire configuration diagram of the mobile terminalapparatus;

FIG. 9 is a functional block diagram of the base station apparatus; and

FIG. 10 is a functional block diagram of the mobile terminal apparatus.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a diagram to explain a frequency usage state when mobilecommunications are performed in downlink. In addition, in all figures toexplain the Embodiment, components having the same functions areassigned the same reference numerals to omit redundant descriptions. Theexample as shown in FIG. 1 is of the frequency usage state in the caseof coexistence of LTE-A systems that are first communication systemshaving first relatively wide system bands comprised of a plurality ofcomponent carriers, and LTE systems that are second communicationsystems having a second relatively narrow system band (herein, comprisedof a single component carrier). In the LTE-A systems, for example, radiocommunications are performed with a variable system bandwidth of 100 MHzor less, and in the LTE systems, radio communications are performed witha variable system bandwidth of 20 MHz or less. The system band of theLTE-A system is at least one base frequency region (component carrier:CC) with a system band of the LTE system as a unit. Thus integrating aplurality of base frequency regions to broaden the band is referred toas carrier aggregation.

For example, in FIG. 1, the system band of the LTE-A system is a systemband (20 MHz×5-100 MHz) containing bands of five component carrierswhere the system band (base band: 20 MHz) of the LTE system is onecomponent carrier. In FIG. 1, a mobile terminal apparatus UE (UserEquipment) #1 is a mobile terminal apparatus supporting the LTE-A system(also supporting the LTE system), and has the system band of 100 MHz,UE#2 is a mobile terminal apparatus supporting the LTE-A system (alsosupporting the LTE system), and has the system band of 40 MHz (20MHz×2-40 MHz), and UE#3 is a mobile terminal apparatus supporting theLTE system (not supporting the LTE-A system), and has the system band of20 MHz (base band).

In addition, mobile terminal apparatus UEs of LTE system (Rel. 8) andits successor system (LTE-A system) support a Half-duplex FDD scheme(hereinafter, referred to as HD-FDD) as a duplex scheme. In HD-FDD, asshown in FIG. 2, uplink transmission/reception and downlinktransmission/reception of a mobile terminal apparatus UE is divided bothin frequency and time. Accordingly, the mobile terminal apparatus doessimultaneously not perform uplink transmission and downlink reception.

In this case, in switching from downlink to uplink, the mobile terminalapparatus gives priority to transmitting an uplink subframe from thebeginning, and ignores an end portion of a downlink subframe. Meanwhile,in switching from uplink to downlink, the mobile terminal apparatuscontrols uplink transmission timing to reserve a time to switch todownlink. However, such an operation of the mobile terminal apparatus isdependent on scheduling of the base station apparatus, and when uplinktransmission and downlink reception occurs at the same time, there is aproblem that the mobile terminal apparatus is not able to operateproperly.

Therefore, the inventors of the present invention arrived at theinvention to solve the problems. In other words, it is the gist of theinvention to cause a mobile terminal apparatus to performtransmission/reception based on a priority relationship between anuplink signal and a downlink signal when uplink transmission timing anddownlink reception timing overlaps each other in the mobile terminalapparatus. By this means, it is possible to optimize the operation ofthe mobile terminal apparatus to which is applied HD-FDD.

Herein, described is the operation of the mobile terminal apparatus whenuplink transmission timing and downlink reception timing overlaps eachother. FIG. 3 contains operation explanatory views of the mobileterminal apparatus when uplink transmission timing and downlinkreception timing overlaps each other.

When uplink transmission timing and downlink reception timing overlapseach other in a mobile terminal apparatus, the mobile terminal apparatusperforms following four patterns of operation corresponding to thepriority relationship between an uplink signal and a downlink signal. Ina first pattern as shown in FIG. 3A, the mobile terminal apparatus givesa higher priority to transmission processing of an uplink signal thanreception processing of a downlink signal. For example, when the uplinksignal is more important (has a higher priority) than the downlinksignal, the mobile terminal apparatus gives priority to transmissionprocessing of the uplink signal. In addition, the mobile terminalapparatus does always not give priority to transmission processing of anuplink signal every time, and is capable of giving priority to receptionprocessing of a downlink signal in a particular subframe correspondingto instructions from a base station apparatus.

In a second pattern as shown in FIG. 3B, the mobile terminal apparatusgives a higher priority to reception processing of a downlink signalthan transmission processing of an uplink signal. For example, when thedownlink signal is more important (has a higher priority) than theuplink signal, the mobile terminal apparatus gives priority to receptionprocessing of the downlink signal. In addition, the mobile terminalapparatus does always not give priority to reception processing of adownlink signal every time, and is capable of giving priority totransmission processing of an uplink signal in a particular subframecorresponding to instructions from a base station apparatus.

In a third pattern as shown in FIG. 3C, the mobile terminal apparatusperforms both transmission processing of an uplink signal and receptionprocessing of a downlink signal in a single subframe. For example, themobile terminal apparatus gives priority to reception processing of thedownlink signal up to some point of a subframe, while giving priority totransmission processing of the uplink signal in remaining symbols. Inthis case, by using a PUCCH format for HD-FDD or PRACH format for HD-FDDas described later, the mobile terminal apparatus may performtransmission processing of an uplink signal and reception processing ofa downlink signal in the same subframe.

In a fourth pattern as shown in FIG. 3D, the mobile terminal apparatusperforms neither transmission processing of an uplink signal norreception processing of a downlink signal. For example, when the uplinksignal and downlink signal are both important (priorities are the same),the mobile terminal apparatus regards as erroneous detection of signals,and halts transmission/reception processing of the downlink signal anduplink signal.

Described next is the priority relationship between uplink signals anddownlink signals. FIG. 4 is a table showing an example of the priorityrelationship between uplink signals and downlink signals. In addition,the priority relationship and kinds of signals as shown in FIG. 4 arenot limited thereto, and are capable of being modified as appropriate.

Herein, as uplink signals, exemplified are a PUSCH signal, Periodic CQI(Channel Quality Indicator), ACK (Acknowledgement)/NACK (NegativeAcknowledgement), Positive SR (Scheduling Request), SRS (SoundingReference Signal), and PRACH signal. The PUSCH signal is transmitted ona PUSCH (Physical Uplink Shared Channel) as an uplink data channelshared among a plurality of mobile terminals, and includes user data andcontrol information of higher layer. The Periodic CQI is transmitted ona PUCCH (Physical Uplink Control Channel) as an uplink control channel,and is channel quality information of downlink required for schedulingof downlink user data and adaptive link control.

The ACK/NACK is response information to a PDSCH transmitted on thePUCCH. The Positive SR is transmitted on the PUCCH, and requestinformation for requesting a base station apparatus to add to schedulingin order for the mobile terminal apparatus to transmit newly occurringdata. The SRS is a reference signal used for measurement of a CQI ofuplink for each frequency of the mobile terminal apparatus. The PRACHsignal is transmitted on a PRACH (Physical Random Access Channel) as anaccess channel, and is a collision type signal for the mobile terminalapparatus to perform setting of a communication start and the like ininitial access.

Further, herein, as downlink signals, exemplified area PDSCH signal,PDCCH signal, PHICH signal, CSI-RS (Channel State Information—ReferenceSignal), and PBCH signal. The PDSCH signal is transmitted on a PDSCH(Physical Downlink Shared Channel) as a downlink data channel sharedamong mobile terminal apparatuses, and includes user data and controlinformation of higher layer. The PDCCH signal is transmitted on a PDCCH(Physical Downlink Control Channel) as a downlink control channel, andincludes scheduling information of the PUSCH and PDCCH by a schedulerand the like.

The PHICH signal is transmitted on a PHICH (Physical HARQ IndicatorChannel) as a downlink control channel, and is ACK/NACK (responseinformation) to the PUSCH. The CSI-RS is a reference signal used in CSImeasurement for CQI, PMI (Precoding Matrix Indicator), RI (RankIndicator) and the like as a channel state. The PBCH signal istransmitted on a PBCH (Physical Broadcast Channel) as a broadcastchannel, and includes system-specific and cell-specific controlinformation broadcasted to the entire cell.

The priority relationship between each uplink signal and each downlinksignal described above will be described below. The priorityrelationship is set on both the mobile terminal apparatus and the basestation apparatus, is used by the mobile terminal apparatus in selectionof transmission/reception processing, and is used by the base stationapparatus mainly in demodulation of an uplink signal from the mobileterminal apparatus.

As shown in FIG. 4, the priority of a PUSCH signal in uplink is definedto be the same as the priority of a PDSCH signal in downlink.Accordingly, when transmission timing of the PUSCH signal and receptiontiming of the PDSCH signal overlaps each other, the mobile terminalapparatus neither transmits nor receives any of the signals, and regardsas erroneous detection of signals.

The priority of a PUSCH signal in uplink is defined to be higher thanthe priority of a PDCCH signal in downlink. Accordingly, whentransmission timing of the PUSCH signal and reception timing of thePDCCH signal overlaps each other, the mobile terminal apparatustransmits the PUSCH signal. In addition, the mobile terminal apparatusmay give a higher priority to reception of the PDCCH signal thantransmission of the PUSCH signal in a particular subframe. Theparticular subframe may be notified semi-statically from the basestation apparatus to the mobile terminal apparatus by RRC signaling orthe like, or may be notified dynamically from the base station apparatusto the mobile terminal apparatus by adding a control bit of the PDCCHsignal.

The priority of a PUSCH signal in uplink is defined to be lower than thepriority of a PHICH signal in downlink. Accordingly, when transmissiontiming of the PUSCH signal and reception timing of the PHICH signaloverlaps each other, the mobile terminal apparatus receives the PHICHsignal.

The priority of a PUSCH signal in uplink is defined to be higher thanthe priority of a CSI-RS in downlink. Accordingly, when transmissiontiming of the PUSCH signal and reception timing of the CSI-RS overlapseach other, the mobile terminal apparatus transmits the PUSCH signal.

The priority of a PUSCH signal in uplink is defined to be higher thanthe priority of a PBCH signal in downlink. Accordingly, whentransmission timing of the PUSCH signal and reception timing of the PBCHsignal overlaps each other, the mobile terminal apparatus transmits thePUSCH signal. In addition, the mobile terminal apparatus may give ahigher priority to reception of the PBCH signal than transmission of thePUSCH signal in a particular subframe. The particular subframe may benotified by RRC signaling or the like, or may be notified by adding acontrol bit of the PDCCH signal.

The priority of a Periodic CQI in uplink is defined to be higher thanthe priority of a PDSCH signal in downlink. Accordingly, whentransmission timing of the Periodic CQI and reception timing of thePDSCH signal overlaps each other, the mobile terminal apparatustransmits the Periodic CQI.

The priority of a Periodic CQI in uplink is defined to be higher thanthe priority of a PDCCH signal in downlink. Accordingly, whentransmission timing of the Periodic CQI and reception timing of thePDCCH signal overlaps each other, the mobile terminal apparatustransmits the Periodic CQI. In addition, the mobile terminal apparatusmay perform transmission of the Periodic CQI and reception of the PDCCHsignal in the same subframe, using a PUCCH format for HD-FDD. The PUCCHformat for HD-FDD will specifically be described later.

The priority of a Periodic CQI in uplink is defined to be lower than thepriority of a PHICH signal in downlink. Accordingly, when transmissiontiming of the Periodic CQI and reception timing of the PHICH signaloverlaps each other, the mobile terminal apparatus receives the PHICH.In addition, the mobile terminal apparatus may perform transmission ofthe Periodic CQI and reception of the PHICH signal in the same subframe,using the PUCCH format for HD-FDD.

The priority of a Periodic CQI in uplink is defined to be higher thanthe priority of a CSI-RS in downlink. Accordingly, when transmissiontiming of the Periodic CQI and reception timing of the CSI-RS overlapseach other, the mobile terminal apparatus transmits the Periodic CQI. Inaddition, the mobile terminal apparatus may give a higher priority toreception of the CSI-RS than transmission of the Periodic CQI in aparticular subframe. The particular subframe may be notified by RRCsignaling or the like, or may be notified by adding a control bit to thePDCCH signal.

The priority of a Periodic CQI in uplink is defined to be higher thanthe priority of a PBCH signal in downlink. Accordingly, whentransmission timing of the Periodic CQI and reception timing of the PBCHsignal overlaps each other, the mobile terminal apparatus transmits thePeriodic CQI. In addition, the mobile terminal apparatus may give ahigher priority to reception of the PBCH signal than transmission of thePeriodic CQI in a particular subframe. The particular subframe may benotified by RRC signaling or the like, or may be notified by adding acontrol bit to the PDCCH signal.

The priority of ACK/NACK in uplink is defined to be higher than thepriority of a PDSCH signal in downlink. Accordingly, when transmissiontiming of ACK/NACK and reception timing of the PDSCH signal overlapseach other, the mobile terminal apparatus transmits ACK/NACK.

The priority of ACK/NACK in uplink is defined to be higher than thepriority of a PDCCH signal in downlink. Accordingly, when transmissiontiming of ACK/NACK and reception timing of the PDCCH signal overlapseach other, the mobile terminal apparatus transmits ACK/NACK. Inaddition, the mobile terminal apparatus may perform transmission ofACK/NACK and reception of the PDCCH signal in the same subframe, usingthe PUCCH format for HD-FDD.

The priority of ACK/NACK in uplink is defined to be the same as thepriority of a PHICH signal in downlink. Accordingly, when transmissiontiming of ACK/NACK and reception timing of the PHICH signal overlapseach other, the mobile terminal apparatus neither transmits nor receivesany of the signals, and regards as erroneous detection of signals.

The priority of ACK/NACK in uplink is defined to be higher than thepriority of a CSI-RS in downlink. Accordingly, when transmission timingof ACK/NACK and reception timing of the CSI-RS overlaps each other, themobile terminal apparatus transmits ACK/NACK.

The priority of ACK/NACK in uplink is defined to be higher than thepriority of a PBCH signal in downlink. Accordingly, when transmissiontiming of ACK/NACK and reception timing of the PBCH signal overlaps eachother, the mobile terminal apparatus transmits ACK/NACK.

The priority of a Positive SR in uplink is defined to be lower than thepriority of a PDSCH signal in downlink. Accordingly, when transmissiontiming of the Positive SR and reception timing of the PDSCH signaloverlaps each other, the mobile terminal apparatus receives the PDSCHsignal.

The priority of a Positive SR in uplink is defined to be higher than thepriority of a PDCCH signal in downlink. Accordingly, when transmissiontiming of the Positive SR and reception timing of the PDCCH signaloverlaps each other, the mobile terminal apparatus transmits thePositive SR. In addition, the mobile terminal apparatus may performtransmission of the Positive SR and reception of the PDCCH signal in thesame subframe, using the PUCCH format for HD-FDD.

The priority of a Positive SR in uplink is defined to be lower than thepriority of a PHICH signal in downlink. Accordingly, when transmissiontiming of the Positive SR and reception timing of the PHICH signaloverlaps each other, the mobile terminal apparatus receives the PHICHsignal. In addition, the mobile terminal apparatus may performtransmission of the Positive SR and reception of the PHICH signal in thesame subframe, using the PUCCH format for HD-FDD.

The priority of a Positive SR in uplink is defined to be higher than thepriority of a CSI-RS in downlink. Accordingly, when transmission timingof the Positive SR and reception timing of the CSI-RS overlaps eachother, the mobile terminal apparatus transmits the Positive SR.

The priority of a Positive SR in uplink is defined to be higher than thepriority of a PBCH signal in downlink. Accordingly, when transmissiontiming of the Positive SR and reception timing of the PBCH signaloverlaps each other, the mobile terminal apparatus transmits thePositive SR. In addition, the mobile terminal apparatus may give ahigher priority to reception of the PBCH signal than transmission of thePositive SR in a particular subframe. The particular subframe may benotified by RRC signaling or the like, or may be notified by adding acontrol bit to the PDCCH signal.

The priority of an SRS in uplink is defined to be higher than thepriority of a PDSCH signal in downlink. Accordingly, when transmissiontiming of the SRS and reception timing of the PDSCH signal overlaps eachother, the mobile terminal apparatus transmits the SRS. In addition,although details will be described later, the base station apparatus maytransmit the SRS in uplink after receiving the PDSCH signal up to somepoint in downlink.

An SRS in uplink is assigned to a different symbol from that of a PDCCHsignal in downlink in the same subframe. Accordingly, transmission ofthe SRS and reception of the PDCCH is performed in the same subframe. Inaddition, priories may be defined or may not be defined between an SRSand a PDCCH signal.

An SRS in uplink is assigned to a different symbol from that of a PHICHsignal in downlink in the same subframe. Accordingly, transmission ofthe SRS and reception of the PHICH is performed in the same subframe. Inaddition, priories may be defined or may not be defined between an SRSand a PHICH signal.

When an SRS in uplink is assigned to a different symbol from that of aCSI-RS in downlink in the same subframe, transmission of the SRS andreception of the CSI-RS is performed in the same subframe. In this case,priories may be defined or may not be defined between an SRS and aCSI-RS. Meanwhile, when an SRS is assigned to the same symbol as that ofa CSI-RS in the same subframe, one of priorities of the SRS and CSI-RSis defined to be higher. By this means, priority is given to processingof a signal of a higher priority between the SRS and the CSI-RS.

An SRS in uplink is assigned to a different symbol from that of a PBCHsignal in downlink in the same subframe. Accordingly, transmission ofthe SRS and reception of the PBCH signal is performed in the samesubframe. In addition, priories may be defined or may not be definedbetween an SRS and a PBCH signal.

The priority of a PRACH signal in uplink is defined to be lower than thepriority of a PDSCH signal in downlink. Accordingly, when transmissiontiming of the PRACH signal and reception timing of the PDSCH signaloverlaps each other, the mobile terminal apparatus receives the PDSCHsignal.

The priority of a PRACH signal in uplink is defined to be higher thanthe priority of a PDCCH signal in downlink. Accordingly, whentransmission timing of the PRACH signal and reception timing of thePDCCH signal overlaps each other, the mobile terminal apparatustransmits the PRACH signal. In addition, the mobile terminal apparatusmay perform transmission of the PRACH signal and reception of the PDCCHsignal in the same subframe, using a PRACH format for HD-FDD.

The priority of a PRACH signal in uplink is defined to be lower than thepriority of a PHICH signal in downlink. Accordingly, when transmissiontiming of the PRACH signal and reception timing of the PHICH signaloverlaps each other, the mobile terminal apparatus receives the PHICHsignal. In addition, the mobile terminal apparatus may performtransmission of the PRACH signal and reception of the PHICH signal inthe same subframe, using the PRACH format for HD-FDD.

The priority of a PRACH signal in uplink is defined to be higher thanthe priority of a CSI-RS in downlink. Accordingly, when transmissiontiming of the PRACH signal and reception timing of the CSI-RS overlapseach other, the mobile terminal apparatus transmits the PRACH signal.

The priority of a PRACH signal in uplink is defined to be higher thanthe priority of a PBCH signal in downlink. Accordingly, whentransmission timing of the PRACH signal and reception timing of the PBCHsignal overlaps each other, the mobile terminal apparatus transmits thePRACH signal. In addition, the mobile terminal apparatus may give ahigher priority to reception of the PBCH signal than transmission of thePRACH signal in a particular subframe. The particular subframe may benotified by RRC signaling or the like, or may be notified by adding acontrol bit of the PDCCH signal.

By thus defining the priority relationship between an uplink signal anda downlink signal, even when transmission timing of the uplink signaland reception timing of the downlink signal overlaps each other, it ispossible to cause the mobile terminal apparatus to performtransmission/reception processing of an important signal withreliability. In addition, the priority relationship as described aboveis defined while giving a higher priority mainly to an uplink signalthan a downlink signal, but is not limited thereto. The priorityrelationship is capable of being modified as appropriate correspondingto the network configuration, base station apparatus configuration,mobile terminal apparatus configuration and the like.

Transmission/reception methods of uplink signal and downlink signal inthe same subframe as described above will specifically be described withreference to FIG. 5. FIG. 5 contains explanatory views oftransmission/reception methods of uplink signal and downlink signal inthe same subframe.

A first transmission/reception method as shown in FIG. 5A is atransmission/reception method in which a mobile terminal apparatusreceives a downlink signal up to some point in a subframe, and then,transmits an uplink signal in remaining symbols. Herein, the descriptionis given by exemplifying a PDCCH signal and PDSCH signal as downlinksignals, and an SRS as an uplink signal, but is not limited to thesesignals, and it is possible to modify as appropriate.

Generally, an uplink SRS is assigned to a different symbol from that ofa downlink PDCCH signal in the same subframe, but overlaps a symbolassigned to part of a downlink PDSCH signal. Therefore, as shown in FIG.5A, the mobile terminal apparatus ignores last several symbols (2symbols in this Embodiment) of the PDSCH signal for the SRS. The mobileterminal apparatus receives the PDCCH signal of first 3 symbols from thebase station apparatus, while receiving the PDSCH signal up to symbolstwo-symbol-before the last symbol. Subsequently, the mobile terminalapparatus uses a symbol immediately before the last symbol as a guardinterval to switch from the downlink reception processing to the uplinktransmission processing, and transmits the SRS to the base stationapparatus in the last symbol.

Further, the base station apparatus may perform rate matching processingor puncturing processing on a PDSCH signal to transmit the PDSCH signalwith two symbols being vacant corresponding to an SRS and guard intervalreserved in a single subframe. In this case, the base station apparatusperforms the rate matching processing or the like of the PDSCH signalbased on the priority relationship defined between the uplink signal andthe downlink signal. The mobile terminal apparatus receives the PDCCHsignal and PDSCH signal from the base station apparatus. Subsequently,the mobile terminal apparatus uses a symbol immediately before the lastsymbol as a guard interval to switch from the downlink receptionprocessing to the uplink transmission processing, and transmits the SRSto the base station apparatus in the last symbol reserved for the SRS.

In addition, in the above-mentioned first transmission/reception method,the downlink signal is received up to some point, and then, the uplinksignal is received in the remaining symbols. Alternatively, the uplinksignal may be transmitted up to some point, and then, the downlinksignal may be received in the remaining symbols. Further, in FIG. 5A, itis preferable that last two symbols of the PDSCH signal are not assignedimportant data.

A second transmission/reception method as shown in FIGS. 5B and 5C is atransmission/reception method for performing transmission of an uplinksignal and reception of a downlink signal in the same subframe, using asignal format for HD-FDD in a single subframe. Herein, the descriptionis given by exemplifying a PDCCH signal and PHICH signal that aredownlink L1/L2 control signals as downlink signals, and a PUCCH signaland PRACH signal as uplink signals, but is not limited to these signals,and it is possible to modify as appropriate.

Generally, a PUCCH signal in uplink is assigned to the entire subframe,and therefore, overlaps symbols assigned to a PDCCH signal and PHICHsignal in downlink in the same subframe. Therefore, as shown in FIG. SB,the mobile terminal apparatus uses a PUCCH format for HD-FDD in whichfirst several symbols (4 symbols in this Embodiment) of a PUCCH arepunctured or undergo rate matching so as to avoid a PDCCH signal andPHICH signal. The mobile terminal apparatus receives the PDCCH signaland PHICH signal from the base station apparatus in first 3 symbols ofthe PUCCH format for HD-FDD undergoing puncturing or the like.Subsequently, the mobile terminal apparatus uses a 4th symbol of thePUCCH format for HD-FDD as a guard interval to switch from the downlinkreception processing to the uplink transmission processing, andtransmits the PUCCH signal to the base station apparatus in theremaining symbols.

Further, generally, a PRACH signal in uplink is assigned to the entiresubframe, and therefore, overlaps symbols assigned to a PDCCH signal andPHICH signal in downlink in the same subframe. Therefore, as shown inFIG. 5C, the mobile terminal apparatus uses a PRACH format for HD-FDD inwhich first several symbols (4 symbols in this Embodiment) of a PRACHare punctured so as to avoid a PDCCH signal and PHICH signal. The mobileterminal apparatus receives the PDCCH signal and PHICH signal from thebase station apparatus in first 3 symbols of the PRACH format for HD-FDDundergoing puncturing. Subsequently, the mobile terminal apparatus usesa 4th symbol of the PRACH format for HD-FDD as a guard interval toswitch from the downlink reception processing to the uplink transmissionprocessing, and transmits the PRACH signal to the base station apparatusin the remaining symbols.

Moreover, the base station apparatus may use an uplink signal format forHD-FDD in which a part of symbols of an uplink signal undergoespuncturing or rate matching so as to avoid a downlink signal. The mobileterminal apparatus receives a PUSCH signal of a part of the uplinksignal format, while transmitting an uplink signal in the remainingsymbols.

In addition, in the above-mentioned second transmission/receptionmethod, a signal format for HD-FDD may be used with first severalsymbols being vacant, or a signal format for HD-FDD may be used withlast several symbols being vacant or middle several symbols beingvacant. Further, an uplink signal format and downlink signal format maybe combined to use.

Moreover, the transmission/reception method of uplink signal anddownlink signal in the same subframe is not limited to the firsttransmission/reception method and the second transmission/receptionmethod. Any method is capable of being used, as long as the methodenables the mobile terminal apparatus to perform transmission processingof an uplink signal and reception processing of a downlink signal in thesame subframe.

A radio communication system according to the Embodiment of theinvention will specifically be described herein. FIG. 6 is anexplanatory view of a system configuration of the radio communicationsystem according to this Embodiment. In addition, the radiocommunication system as shown in FIG. 6 is a system including the LTEsystem or SUPER 3G, for example. Further, the radio communication systemmay be called IMT-Advanced or may be called 4G.

As shown in FIG. 6, the radio communication system 1 includes the basestation apparatus 20, and a plurality of mobile terminal apparatuses 10(10 ₁, 10 ₂, 10 ₃, . . . , 10 _(n), n is an integer where n>0) thatcommunicate with the base station apparatus 20 and is comprised thereof.The base station apparatus 20 is connected to an upper station apparatus30, and the upper station apparatus 30 is connected to a core network40. The mobile terminal apparatuses 10 are capable of communicating withthe base station apparatus 20 in a cell 50. In addition, for example,the upper station apparatus 30 includes an access gateway apparatus,radio network controller (RNC), mobility management entity (MME), etc.,but is not limited thereto.

Each of the mobile terminal apparatuses (10 ₁, 10 ₂, 10 ₃, . . . , 10_(n)) includes an LTE terminal and LTE-A terminal, and is described as amobile terminal apparatus 10 unless otherwise specified in the followingdescription. Further, for convenience in description, the description isgiven while assuming that equipment that performs radio communicationswith the base station apparatus 20 is the mobile terminal apparatus 10,and more generally, the equipment may be user equipment (UE) includingmobile terminal apparatuses and fixed terminal apparatuses.

In the radio communication system 1, as a radio access scheme, OFDMA(Orthogonal Frequency Division Multiple Access) is applied in downlink,while SC-FDMA (Single-Carrier Frequency Division Multiple Access) isapplied in uplink, but the uplink radio access scheme is not limitedthereto. OFDMA is a multicarrier transmission scheme for dividing afrequency band into a plurality of narrow frequency bands (subcarriers),and mapping data to each subcarrier to perform communications. SC-FDMAis a single-carrier transmission scheme for dividing the system bandinto bands comprised of a single or consecutive resource blocks for eachterminal so that a plurality of terminals uses mutually different bands,and thereby reducing interference among the terminals.

Referring to FIG. 7, described is the entire configuration of the basestation apparatus 20 according to this Embodiment. The base stationapparatus 20 is provided with a transmission/reception antenna 201,transmission/reception section 203, baseband signal processing section204, call processing section 205 and transmission path interface 206.The user data to transmit from the base station apparatus 20 to themobile terminal apparatus 10 in downlink is input to the baseband signalprocessing section 204 via the transmission path interface 206 from theupper station apparatus 30.

The baseband signal processing section 204 performs PDCP layerprocessing, segmentation and concatenation of the user data, RLC (RadioLink Control) layer transmission processing such as transmissionprocessing of RLC retransmission control, MAC (Medium Access Control)retransmission control e.g. HARQ transmission processing, scheduling,transmission format selection, channel coding, Inverse Fast FourierTransform processing and precoding processing. Further, on a signal ofthe Physical Downlink Control Channel that is a downlink controlchannel, the section 204 also performs transmission processing ofchannel coding, Inverse Fast Fourier Transform and the like.

Further, the baseband signal processing section 204 notifies the mobileterminal apparatus 10 of control information for communications in thecell on the broadcast channel. For example, the control informationincludes the system bandwidth in uplink or downlink, identificationinformation (Root Sequence Index) of a root sequence to generate asignal of a random access preamble on the PRACH, etc.

The transmission/reception section 203 converts the frequency of thebaseband signal output from the baseband signal processing section 204into a radio frequency band, and amplifies the signal to output to thetransmission/reception antenna 201.

Meanwhile, with respect to signals transmitted from the mobile terminalapparatus 10 to the base station apparatus 20 in uplink, a radiofrequency signal received in the transmission/reception antenna 201 isamplified in the transmission/reception section 203, while beingconverted into a baseband signal, and is input to the baseband signalprocessing section 204.

The baseband signal processing section 204 performs FFT processing, IDFTprocessing, error correcting decoding, reception processing of MACretransmission control, and reception processing of RLC layer and PDCPlayer on the user data included in the baseband signal received inuplink. The decoded signal is transferred to the upper station apparatus30 via the transmission path interface 206.

The call processing section 205 performs call processing such as settingand release of the communication channel, status management of the basestation apparatus 20, and management of radio resources.

Referring to FIG. 8, described next is the entire configuration of themobile terminal apparatus 10 according to this Embodiment. The LTEterminal and the LTE-A terminal have the same configuration of principalpart of hardware, and are not distinguished to describe. The mobileterminal apparatus 10 is provided with a transmission/reception antenna101, transmission/reception section 103, baseband signal processingsection 104 and application section 105.

With respect to data in downlink, a radio frequency signal received inthe transmission/reception antenna 101 is amplified in thetransmission/reception section 103, while being subjected to frequencyconversion, and is converted into a baseband signal. The baseband signalis subjected to FFT processing, error correcting decoding, receptionprocessing of retransmission control, etc. in the baseband signalprocessing section 104. Among the data in downlink, the user data indownlink is transferred to the application section 105. The applicationsection 105 performs processing concerning layers higher than thephysical layer and MAC layer and the like. Further, among the data indownlink, the broadcast information is also transferred to theapplication section 105.

Meanwhile, with respect to user data in uplink, the application section105 inputs the data to the baseband signal processing section 104. Thebaseband signal processing section 104 performs transmission processingof retransmission control (HARQ), channel coding, DFT processing andIFFT processing. The transmission/reception section 103 converts thefrequency of the baseband signal output from the baseband signalprocessing section 104 into a radio frequency band, and amplifies thesignal to output to the transmission/reception antenna 101.

Functional blocks of the base station apparatus according to thisEmbodiment will be described with reference to FIG. 9. In addition, FIG.9 mainly shows functional blocks of the baseband processing section andtransmission/reception section. Further, FIG. 9 simplifies the basebandprocessing section and transmission/reception section, and it is assumedto have configurations generally provided in the baseband processingsection and transmission/reception section. The base station apparatus20 has a PBCH signal generating section 211, PDCCH signal generatingsection 212, PHICH signal generating section 213, PDSCH signalgenerating section 214, CSI-RS generating section 215, physical channelmultiplexing section 216, IFFT section 217, CP adding section 218, andtransmission RF circuit 203 b, as a transmission system.

The PBCH signal generating section 211 generates a PBCH signal includingbasic parameters of a bandwidth, control channel configuration, etc. ThePDCCH signal generating section 212 generates a PDCCH signal includingformat information such as a modulation method and coding rate, inaddition to scheduling information of the PUSCH signal and PDSCH signal,for each user, based on allocation by a scheduler 231. The PHICH signalgenerating section 213 generates a PHICH signal for HARQ (HybridAutomatic Repeat reQuest) to the PUSCH signal based on allocation by thescheduler 231. The PDSCH signal generating section 214 generates a PDSCHsignal including user data and control information of a higher layershared by a plurality of mobile terminal apparatuses 10, based onallocation by the scheduler 231. The CSI-RS generating section 215generates a CSI-RS used only for measurement of channel stateinformation.

The physical channel multiplexing section 216 multiplexes downlinksignals which are coded and modulated in respective signal generatingsections to input to the IFFT section 217. The IFFT section 217 performsIFFT (Inverse Fast Fourier Transform) on the multiplexed downlinksignal, and transforms the signal in the frequency domain into atime-series signal. The CP adding section 218 inserts a cyclic prefix inthe downlink signal. Then, the downlink signal passes through thetransmission RF circuit 203 b, and is transmitted from thetransmission/reception antenna 201 via a duplexer 203 c provided inbetween the transmission system and a reception system.

As the reception system, the base station apparatus 20 has a PUSCHsignal demodulation•decoding section 221, PUCCH signaldemodulation•decoding section 222, PRACH signal reception section 223,SRS reception section 224, physical channel dividing section 225, FFTsection 226, CP removing section 227 and reception RF circuit 203 a. Anuplink signal received in the transmission/reception antenna 201 isinput to the CP removing section 227 via the duplexer 203 c andreception RF circuit 203 a. The CP removing section 227 removes thecyclic prefix from the uplink signal to input to the FFT section 226.The FFT section 226 performs Fast Fourier Transform (FFT) on the uplinksignal, and transforms the time-series signal into a signal in thefrequency domain to input to the physical channel dividing section 225.The physical channel dividing section 225 divides uplink signalsmultiplexed into the uplink signal into respective signals.

The PUSCH signal demodulation•decoding section 221 demodulates a PUSCHsignal including user data and control information of a higher layershared by a plurality of mobile terminal apparatuses 10, based onallocation by the scheduler 231, and further decodes the signal. ThePUCCH signal demodulation•decoding section 222 demodulates a PUCCHsignal including a Periodic CQI, ACK/NACK to the PDSCH and Positive SR,based on allocation of the scheduler 231, and further decodes thesignal. The PRACH signal reception section 223 receives a collision typePRACH signal used in initial access of the mobile terminal apparatus 10.The SRS reception section 224 receives an SRS to perform scheduling bythe scheduler 231 and adaptive control.

The scheduler 231 controls resource allocation to mobile terminalapparatuses 10 under the base station apparatus corresponding tocommunication quality of the entire system band. The scheduler 231distinguishes between an LTE terminal user and an LTE-A terminal user toperform scheduling. To the scheduler 231 are input transmission data andretransmission instructions from the upper station apparatus 30, and achannel estimation value and CQI of a resource block from the receptionsection that measures the uplink signal. The scheduler 231 performsscheduling of the PDCCH signal, PHICH signal and PDSCH signal, whilereferring to the retransmission instructions input from the upperstation apparatus 30, channel estimation value and CQI. In a propagationpath in mobile communications, variations vary with frequencies byfrequency selective fading. Then, in transmitting user data to mobileterminal apparatuses 10, the scheduler 231 allocates resource blockswith good communication quality for each subframe to each mobileterminal apparatus 10 (called adaptive frequency scheduling). Inadaptive frequency scheduling, a mobile terminal apparatus 10 of goodpropagation path quality is selected and allocated for each resourceblock. Therefore, the scheduler 231 uses CQIs on a basis of a resourceblock transmitted from each mobile terminal apparatus 10 as feedback toallocate resource blocks. Further, the scheduler 231 determines an MCS(coding rate, modulation scheme) meeting a predetermined block errorrate in the allocated resource block. A parameter satisfying the MCSdetermined in the scheduler 231 is set on the PDCCH signal generatingsection 212, PHICH signal generating section 213 and PDSCH signalgenerating section 214.

Further, the scheduler 231 controls demodulation and decoding of thePUSCH signal demodulation•decoding section 221 and PUCCH signaldemodulation•decoding section 222, in consideration of theabove-mentioned priority relationship. When transmission and receptiontiming of uplink and downlink signals in the mobile terminal apparatus10 overlaps each other, the PUSCH signal demodulation•decoding section221 and PUCCH signal demodulation•decoding section 222 need to determinewhether the uplink signal is transmitted to the base station apparatus20. Therefore, the scheduler 231 inputs, to the PUSCH signaldemodulation•decoding section 221 and PUCCH signal demodulation•decodingsection 222, which transmission of the uplink signal or reception of thedownlink signal is given a higher priority in the mobile terminalapparatus 10 in a predetermined subframe based on the above-mentionedpriority relationship.

Furthermore, the base station apparatus 20 has a signal format selectingsection 232. When uplink and downlink signals are received andtransmitted in the same subframe, the signal format selecting section232 selects the signal format as shown in FIGS. 5A to 5C, based onallocation by the scheduler 231. When the transmission/reception methodin the same subframe is controlled on the base station apparatus 20side, the signal format selecting section 232 inputs signal formatinformation to the signal generating sections. For example, based on thesignal format information, on the premise that the mobile terminalapparatus 10 does not receive last several symbols of the subframe asshown in FIG. 5A, the PDSCH signal generating section 214 may performrate matching processing or puncturing processing on the PDSCH signal.Further, for example, the PDSCH signal generating section 214 maygenerate the PDSCH format for HD-FDD in which the PDSCH signal undergoesrate matching or puncturing so as to avoid the downlink signal, based onthe signal format information.

Meanwhile, when the transmission/reception method in the same subframeis controlled on the mobile terminal apparatus 10 side, the signalformat selecting section inputs the signal format information to thedemodulation•decoding sections and reception sections. By this means,even when transmission and reception timing of downlink and uplinksignals overlaps each other in the same subframe, thedemodulation•decoding sections and reception sections are capable ofrecognizing symbols in which an uplink signal is transmitted. Forexample, the PUCCH signal demodulation decoding section 222 recognizessymbols assigned a PUCCH signal in a single subframe based on the signalformat information, demodulates the PUCCH signal, and further decodesthe signal.

Functional blocks of the mobile terminal apparatus according to thisEmbodiment will be described with reference to FIG. 10. In addition,FIG. 10 mainly shows functional blocks of the baseband processingsection and transmission/reception section. Further, FIG. 10 simplifiesthe baseband processing section and transmission/reception section, andit is assumed to have configurations generally provided in the basebandprocessing section and transmission/reception section. The mobileterminal apparatus 10 has a PUSCH signal generating section 111, PUCCHsignal generating section 112, PRACH signal generating section 113, SRSgenerating section 114, physical channel multiplexing section 115, IFFTsection 116, CP adding section 117, and transmission RF circuit 103 b,as a transmission system.

The PUSCH signal generating section 111 generates a PUSCH signal sharedamong a plurality of mobile terminal apparatuses 10 based on schedulinginformation. The PUCCH signal generating section 112 generates a PUCCHsignal including a Periodic CQI, ACK/NACK, and Positive SR. The PRACHsignal generating section 113 generates a collision type PRACH signalused in initial access to the base station apparatus 20. The SRSgenerating section 114 generates an SRS used in scheduling and adaptivecontrol.

The physical channel multiplexing section 115 multiplexes uplink signalswhich are coded and modulated in respective signal generating sectionsto input to the IFFT section 116. The IFFT section 116 performs IFFT(Inverse Fast Fourier Transform) on the multiplexed uplink signal, andtransforms the signal in the frequency domain into a time-series signal.The CP adding section 117 inserts a cyclic prefix in the uplink signal.Then, the uplink signal passes through the transmission RF circuit 103b, and is transmitted from the transmission/reception antenna 101 via aswitch 103 c provided in between the transmission system and a receptionsystem.

As the reception system, the base station apparatus 20 has a PBCH signaldemodulation•decoding section 121, PDCCH signal demodulation•decodingsection 122, PHICH signal demodulation•decoding section 123, PDSCHsignal demodulation•decoding section 124, CSI-RS reception section 125,physical channel dividing section 126, FFT section 127, CP removingsection 128 and reception RF circuit 103 a. A downlink signal receivedin the transmission/reception antenna 101 is input to the CP removingsection 128 via the switch 103 c and reception RF circuit 103 a. The CPremoving section 128 removes the cyclic prefix from the downlink signalto input to the FFT section 127. The FFT section 127 performs FastFourier Transform (FFT) on the downlink signal, and transforms thetime-series signal into a signal in the frequency domain to input to thephysical channel dividing section 126. The physical channel dividingsection 126 divides downlink signals multiplexed into the downlinksignal into respective signals.

The PBCH signal demodulation•decoding section 121 demodulates a PBCHsignal including system information specific to the cell, and furtherdecodes the signal. The PDCCH signal demodulation•decoding section 122demodulates a PDCCH signal including scheduling information of a PUSCHsignal and PDSCH signal for each user, and further decodes the signal.The PDCCH signal demodulation•decoding section 122 inputs schedulinginformation of uplink and downlink to a transmission/receptionchannel•signal format selecting section 131. The PHICH signaldemodulation•decoding section 123 demodulates a PHICH signal to thePUSCH, and further decodes the signal. The PHICH signaldemodulation•decoding section 123 inputs whether or not to retransmitthe PUSCH to the transmission/reception channel•signal format selectingsection 131 based on the PHICH signal. The PDSCH signaldemodulation•decoding section demodulates a PDSCH signal including userdata and control information of a higher layer shared among a pluralityof mobile terminal apparatuses 10, and further decodes the signal. TheCSI-RS reception section 125 demodulates a CSI-RS used only formeasurement of channel state information, and further decodes thesignal.

Further, the mobile terminal apparatus 10 has the transmission/receptionchannel•signal format selecting section 131. The transmission/receptionchannel•signal format selecting section 131 determines a signal of ahigher priority based on the priority relationship between uplink anddownlink signals when transmission and reception timing of uplink anddownlink signals overlaps each other. Then, based on the determinationresult, the transmission/reception channel•signal format selectingsection 131 selects transmission processing of the uplink signal orreception processing of the downlink signal to give priority. Morespecifically, when the transmission processing of the uplink signal isgiven priority, the transmission/reception channel•signal formatselecting section 131 switches the switch 103 c to the transmissionsystem side with switch timing information. By this means, the mobileterminal apparatus 10 transmits the uplink signal via thetransmission/reception antenna 101. When the reception processing of thedownlink signal is given priority, the transmission/receptionchannel•signal format selecting section 131 switches the switch to thereception system side with the switch timing information. By this means,the mobile terminal apparatus 10 receives the downlink signal via thetransmission/reception antenna 101.

In this case, the transmission/reception channel•signal format selectingsection 131 may switch the switch 103 c contrary to the priorityrelationship in a particular subframe notified by RRC signaling or PDCCHsignal. In other words, in the particular subframe, the section 131 maygive priority to reception processing of the downlink signal of a lowerpriority than the uplink signal, or may give priority to transmissionprocessing of the uplink signal of a lower priority than the downlinksignal. Further, when neither transmission processing of the uplinksignal nor reception processing of the downlink signal is performed, thetransmission/reception channel•signal format selecting section 131separates the switch 103 c from the transmission system and receptionsystem with the switch timing information. By this means, the mobileterminal apparatus 10 halts the transmission and reception processing ofuplink signal and downlink signal.

Further, when uplink and downlink signals are transmitted and receivedin the same subframe, the transmission/reception channel•signal formatselecting section 131 selects the signal format shown in any of FIGS. 5Ato 5C. When the transmission/reception method in the same subframe iscontrolled on the mobile terminal apparatus 10 side, thetransmission/reception channel•signal format selecting section 131inputs the signal format information to each signal generating section,each demodulation•decoding section and reception section.

For example, in the first transmission/reception method as shown in FIG.5A, the PDSCH signal demodulation•decoding section 124 demodulates thePDSCH signal while leaving last several symbols based on the signalformat information, and further decodes the signal. Further, the SRSgenerating section 114 generates an SRS in accordance with the lastsymbol. Meanwhile, in the second transmission/reception method as shownin FIG. 5B, the PUCCH signal generating section 112 selects the PUCCHformat for HD-FDD based on the signal format information, and performspuncturing or rate matching on first several symbols to generate a PUCCHsignal. Further, the PDCCH signal demodulation•decoding section 122 andPHICH signal demodulation•decoding section 123 demodulate the PDCCHsignal and PHICH signal assigned to first several symbols based on thesignal format information, and further decode the signals. Moreover, inthe second transmission/reception method as shown in FIG. 5C, the PRACHsignal generating section 113 selects the PRACH format for HD-FDD basedon the signal format information, and performs puncturing on firstseveral symbols to generate a PRACH signal. Further, the PDCCH signaldemodulation•decoding section 122 and PHICH signal demodulation decodingsection 123 demodulate the PDCCH signal and PHICH signal assigned tofirst several symbols based on the signal format information, andfurther decode the signals.

In the transmission/reception in the same subframe, thetransmission/reception channel•signal format selecting section 131inputs the switch timing information to the switch 103 c at a guardinterval provided in the subframe. By this means, transmission of theuplink signal and reception of the downlink signal is switched in asingle subframe.

As described above, according to the mobile terminal apparatus 10according to this Embodiment, when transmission timing of an uplinksignal and reception timing of a downlink signal overlaps each other inthe mobile terminal apparatus, transmission/reception processing isperformed selectively. Accordingly, for the mobile terminal apparatus 10to which is applied HD-FDD, it is possible to cause the apparatus 10 toperform optimal operation when transmission timing of an uplink signaland reception timing of a downlink signal overlaps each other.

In addition, in the above-mentioned Embodiment, indication of aparticular subframe is notified to the mobile terminal apparatus by RRCsignaling or adding a control bit to the PDCCH signal, but is notlimited thereto. The indication may be notified by any method, when themethod enables the mobile terminal apparatus to be notified of theparticular subframe.

Further, in the above-mentioned Embodiment, the priority relationship isset on the base station apparatus and the mobile terminal apparatus, andonly the mobile terminal apparatus may be set for the priorityrelationship. Moreover, the priority relationship may be beforehand seton both the base station apparatus and the mobile terminal apparatus,may be notified from the base station apparatus to the mobile terminalapparatus, or may be notified from the mobile terminal apparatus to thebase station apparatus.

The present invention is not limited to the above-mentioned Embodiment,and is capable of being carried into practice with various modificationsthereof. For example, without departing from the scope of the invention,kinds of uplink signals, kinds of downlink signals, assignment positionsof an uplink signal and downlink signal, the number of functionalblocks, processing procedures and the like in the above-mentioneddescription are capable of being carried into practice withmodifications thereof as appropriate. Further, the invention is capableof being carried into practice with modifications thereof as appropriatewithout departing from the scope of the invention.

The present application is based on Japanese Patent Application No.2011-033388 filed on Feb. 18, 2011, entire content of which is expresslyincorporated by reference herein.

1.-11. (canceled)
 12. A user apparatus that performs radiocommunications with a base station apparatus by a half-duplex scheme,the user apparatus comprising: a transmission/reception circuit thattransmits an uplink signal and receives a downlink signal; and a controlcircuit that controls to transmit the uplink signal after a given guardinterval that is provided to prevent transmission of the uplink signaland reception of the downlink signal from overlapping each other withinone subframe.
 13. The user apparatus according to claim 12, wherein thecontrol circuit controls to multiplex a downlink control signal to abeginning of the one subframe.
 14. The user apparatus according to claim12, wherein the control circuit controls to transmit the uplink signalincluding at least one of an uplink reference signal, an uplink controlsignal and a random access channel signal after the given guardinterval.
 15. The user apparatus according to claim 12, wherein thecontrol circuit controls to transmit the uplink signal after the givenguard interval that is provided to prevent transmission of the uplinksignal and reception of the downlink signal from overlapping each otherwithin the one subframe, in accordance with signal format information.16. A base station apparatus that performs radio communications with auser apparatus by a half-duplex scheme, the base station apparatuscomprising: a transmission/reception circuit that receives an uplinksignal and transmits a downlink signal; and a control circuit thatcontrols to receive the uplink signal after a given guard interval thatis provided to prevent reception of the uplink signal and transmissionof the downlink signal from overlapping each other within one subframe.17. A communication control method for a user apparatus that performsradio communications with a base station apparatus by a half-duplexscheme, the communication control method comprising the steps of:transmitting an uplink signal and receiving a downlink signal; andcontrolling to transmit the uplink signal after a given guard intervalthat is provided to prevent transmission of the uplink signal andreception of the downlink signal from overlapping each other within onesubframe.